In this way, the development of a simple, highly-sensitive and specific rapid-testing is being planned, which will verify the existence of disease-causing genes such as the so-called “cancer gene”, also, however, of bacteria, viruses and genetically changed organisms. As well as an easier and improved diagnosis, the joint project also wants to help cancer and gene therapy onto its feet: Transport containers and Trojan horses aim to make possible the targeted transport of the substance into the single cell. A building-block system is planned for these innovative drug-delivery systems: Using the latter, the surfaces of the substance-filled capsule are modified to such an extent that they can be dispatched to certain cell types as required. “In both of the research areas – diagnosis and therapy – we are relying on LBL capsules with modified surfaces that will carry oligonucleotides on their outer surfaces”, explains project coordinator Lars Dähne of Capsulution. The short filaments which are made up of building blocks of genetic substance act as recognition sequences, can, however, also have a therapeutic effect as a substance.
The basis of the diagnosis kits are tiny particles: “The new nanoparticles proving the existence of biomolecules such as DNA and RNA will consist of a magnetic core and a functionalised shell”, describes Dähne and goes on to add: “We are building the shell of the core-shell particle layer-wise, with the help of our LBL-Technology®. In the next step, we couple the required nucleotide fragments onto the rough LBL surface”. The nucleic acid filaments then stick out of the particles like hooks. When used in the rapid testing, the oligonucleotides attract complimentary nucleic acid filaments (fragments) into the samples to be investigated. The evidence of a successful catch or of a hybridisation event is proven by using FRET detection (Fluorescence Resonance Energy Transfer). “Now the core takes the stage”, states Dähne. “Before the detection, magnets can concentrate the particles exactly”. In order to increase the sensitivity of the evidence, his project group wants to work one of the two fluorescent dyes involved into the LBL surface.
The QIAGEN rapid-testing system aims to facilitate the discovery of genetic markers for certain viruses or diseases and therefore press ahead for worldwide prevention and treatment of such diseases. With the new system, neither an concentration, purification nor an amplification of the sought-after biomolecule or gene will be necessary. “We want to develop a method which delivers accurate results, which is reasonably priced and can be carried out by less specialised personnel in the most diverse of laboratories worldwide”, states Dr. Loanna Andreou, Senior Scientist for R&D at QIAGEN. Also, the detection system aims to facilitate identity regulations or legal medical investigations.
For the drug-delivery units, the LBL capsules contain substances which need to be transported to the cells without leakage because only when the capsule has reached its destination cell and has docked on, can the delivered substance influence the cell from the outside or the inside. To enable the capsules to function as transport containers or even as Trojan horses overcoming the cell barriers, a prepared and intended bonding onto biological surfaces needs to be implemented. This can be carried out with the help of oligonucleotides.
The employment of transport capsules and Trojan horses would make enormous therapeutical steps, especially with certain cancer forms such as leukaemia: Here, this employment could lead to practically effect-free medication. Capsulution wants to make use of extra and intracellular drug-delivery units: “The coupling of desired release properties of encapsulated substances with precise cell targeting can be ideally marketed”, explains the BD-Manager Silvana Di Cesare of Capsulution Nanoscience.